I could defeat you could defeat he could defeat we could defeat you could defeat they could defeat
V-ing form
I could be defeating you could be defeating he could be defeating we could be defeating you could be defeating they could be defeating
Perfect
I could have defeated you could have defeated he could have defeated we could have defeated you could have defeated they could have defeated
V-ing perfect
I could have been defeating you could have been defeating he could have been defeating we could have been defeating you could have been defeating they could have been defeating
Negation
Simple form
I couldn't defeat you couldn't defeat he couldn't defeat we couldn't defeat you couldn't defeat they couldn't defeat
V-ing form
I couldn't be defeating you couldn't be defeating he couldn't be defeating we couldn't be defeating you couldn't be defeating they couldn't be defeating
Perfect
I couldn't have defeated you couldn't have defeated he couldn't have defeated we couldn't have defeated you couldn't have defeated they couldn't have defeated
V-ing perfect
I couldn't have been defeating you couldn't have been defeating he couldn't have been defeating we couldn't have been defeating you couldn't have been defeating they couldn't have been defeating
Interrogative form
Simple form
could I defeat? could you defeat? could he defeat? could we defeat? could you defeat? could they defeat?
V-ing form
could I be defeating? could you be defeating? could he be defeating? could we be defeating? could you be defeating? could they be defeating?
Perfect
could I have defeated? could you have defeated? could he have defeated? could we have defeated? could you have defeated? could they have defeated?
V-ing perfect
could I have been defeating? could you have been defeating? could he have been defeating? could we have been defeating? could you have been defeating? could they have been defeating?
Interro-negative form
Simple form
couldn't I defeat? couldn't you defeat? couldn't he defeat? couldn't we defeat? couldn't you defeat? couldn't they defeat?
V-ing form
couldn't I be defeating? couldn't you be defeating? couldn't he be defeating? couldn't we be defeating? couldn't you be defeating? couldn't they be defeating?
Perfect
couldn't I have defeated? couldn't you have defeated? couldn't he have defeated? couldn't we have defeated? couldn't you have defeated? couldn't they have defeated?
V-ing perfect
couldn't I have been defeating? couldn't you have been defeating? couldn't he have been defeating? couldn't we have been defeating? couldn't you have been defeating? couldn't they have been defeating?